/Engine/Plugins/Experimental/Mutable/Source/CustomizableObject/Classes/MuCO/CustomizableObjectInstance.h
Enables the reuse of all possible textures when the instance is updated without any changes in geometry or state (the first update after creation doesn't reuse any) It will only work if the textures aren't compressed, so set the instance to a Mutable state with texture compression disabled WARNING! If texture reuse is enabled, do NOT keep external references to the textures of the instance. The instance owns the textures.
void SetReuseInstanceTextures ( bool bTextureReuseEnabled )